Test lamp



June 4, 1940.` o. s. A. MEscH TEST LAMP Filed Aug. 2, 1938 /NI/ENTOR QSA. MESCH Byjacf ma( Patented June 4, 1940 UNITED STATES ZBAt@ rar nr TEST LABIP Application August 2, 1938,y serial No. 222,638

1 Claim.

This invention relates to Contact spring viewing devices and has for its object the provision of a contact spring viewing device which will be simple and convenient .in use.

In manual and automatic telephone systems, for example, as is well known, a great number of motor magnets are used for operating switching elements in the form of Contact springs upon the movement of their armatures for effecting i" circuit connections, the contact springs being actuated in sets of varying numbers through insulating studs carried by some of the springs and placed in an end-to-end relation adjacent the v cooperating contacts at the free ends of these i" springs.

In such switch spring assemblies, due to the extremely limited space available on the frames on which these motor magnets and associated contact springs are mounted, together with the i space taken by their connecting wires, visual observations and adjustments of the contacts and the gaps between the insulating studs 0peratively interconnecting these contact springs is rendered inconvenient and diflicult, especially i3 when considering that the air-gaps or clearance between the insulating studs must be maintained within a few thousandths of an inch, in order to assure proper operation of the contacts and conm sequently the proper operation of electrical. apparatus controlled by the operation of such switch springs.

According to this invention, a contact spring viewing device is provided in which the light emitted by an electric bulb illuminates a tip of light conducting material from which the light is deflected toward the spaces or gaps between the studs and the contacts which are amplified by a lens clamped on the handle on which the light conducting tip is secured. Means is provided for adjustably positioning the lens relative to the tip, the contacts and their actuating studs for visually observing them. Means is provided whereby the turning movement of a knob re1- ative to the handle controls the energization of the lamp, with means provided for eifecting electrical connections between the elements connecting with the electrodes of the lamp and the incoming wires, such connecting wires being encased in the handle which supports the means 50 for controlling the operation of the lamp.

Other novel features of the invention and advantages will appear from the following description and by the claim appended thereto, reference being had to the accompanying drawing in which:

(Cl. MIL- 2.18) if Fig. 1 is an assembly view showing the reflector tip in position for viewing a contact spring assembly;

Fig. 2 is a partial view showing the reiiector tip and the spring assembly 90 degrees from the position shown in Fig. l;

Fig. 3 is an enlarged longitudinal sectional view showing the lamp out of contact from its associated centrally disposed conducting element; and

Fig. 4 is a partial View in section showing one of the electrodes of the lamp in contact with the centrally disposed conducting element.

In the drawing, I il is a tubular housing made of insulating material. its ends is interiorly screw threaded for receiving a similiarly screw threaded knob II having a longitudinal centrally disposed opening for receiving the stem portion I2 of a light conducting tip RT the function of which will be hereinafter described in detail.

A tubing I3 of insulating material nts into the tubular housing Il! and in the end of this tubing is inserted the reduced portion of a plug I4 of insulating material. This plug has a longitudinal central opening provided for receiving the electric cord I5 having the wires W and WI, shown in Figs. 1 and 3. The housing I l), the tubing i3 and the plug Ill are held against movement relative to each other by a radially disposed pin I6 shown in Fig. 3. The opposite end of tubing I3 is formed obliquely relative to its length for registering with the obliquely shaped end of a conducting sleeve I'I. A conducting core I9 is mounted in sleeve 2B of insulating material in turn fitting the interior of conducting sleeve I1. The sleeve Il and the insulating sleeve 2t are provided with registering openings for permitting the passing of a screw 2| threadedly engaging with a similarly threaded hole in the rear end of core i9, this screw serving for securing the wire W of cord I5 to the core or conducting element I9 While the wire WI of cord I5 is secured to the metallic sleeve Il by a screw 22 as shown in Fig. 3.

The metallic sleeve i'! is provided with a hole 23 shown in Figs. 3 and 4 for receiving one end of a conducting helical spring 24, the other end of this spring engaging the screw-threaded electrode of lamp I8. The spring 2d is normally tensioned, as to force the lamp I8 out of contact from the core I9 upon the unscrewing of knob i i and electrically connects the sleeve i1 to the screwthreaded electrode of bulb I8.

The tip RT which may be made of any light This housing at one ofE conducting material, has a portion X of rectangular cross-section forming a shoulder portion at XI provided for assisting in locating its reector end in position relative to the contact spring assembly or pile-up. The wires W and WI of cord I5 terminate at their opposite ends in clips 23 and 24 provided for securely connecting the electrical bulb to any current source (not shown), While a fastening ring 25, which is clamped over the oord I5, is provided with lug portions 26 and 21 abutting against the end of insulating plug I4 for resisting any pull on the cord I5 and thereby preventing the breaking of the connections at the end of Wires W and WI. A spring clip 30 shown in Fig. l engages the handle I0 and cooperates with the link 3l to form a swivel device for focusing the lens L on the studs SI and S2 and onto the contacts a, b and c at the free end of the contact spring assembly or pile-up SPU.

In the use of this device for the visual observation of the contact spring pile-up shown in Figs. 1 and 2 for example, the knob II is screwed in the tubular housing I0 in position wherein the central electrode of the bulb engages the end core I9 to establish an energizing circuit for the electric bulb I8 through the wire W, the core I9 in contacting engagement with the centrally disposed electrode of the bulb, the other side of the circuit extending through wire WI, the conducting sleeve I'I and the helical spring 28 screwing on the other electrodes of bulb I8.

The light emitted by the bulb I8 passes through the tip end RT and lights the rear sides of the contact springs passing unobstructed between the gaps of contacts a, b and c and through the clearance D between the studs SI and S2, which are visually observed and amplified by the lens L mounted on the swivel device carried by the handle, thus facilitating the viewing and adjustment of the contacts.

It is understood that minor changes may be made in the device of this invention without departing from the scope of the appended claim.

What is claimed is:

A device of the character above described, comprising a tubular handle of insulating material, a sleeve of conducting material, a sleeve of insulating material disposed in end-to-end relation with said conducting sleeve and secured to said handle, a sleeve of insulating material disposed in concentric relation in said conducting sleeve, a core in the last-mentioned sleeve, said core and Said conducting sleeve having means for connection with the ends of incoming electrical wires, a lamp in said handle, a helical spring having one of its ends engaging one electrode of said lamp` and its other end engaging said conducting sleeve for electrically connecting said conducting sleeve to said electrode and normally holding the other electrode of said lamp disengaged from the adjacent end of said core, a knob adjustable longitudinally of said handle for moving said lamp against the tension of said spring in engaged relation with said core for energizing said lamp, said second-mentioned sleeve and said conducting sleeve having registering portions held interengaged by the tension of said spring, and a light conducting element carried by said knob.

ORWAR S. A. MESCH. 

